it's not. WP is one of the most under rated resorts in the area. They have the most consistent snowfall year to year and the vasquez cirque has some way gnarlier terrain than a lot of the northern CO mtns. not to mention the back country options in the area like berthoud pass (my home) are unbeatable at times for snow quality.
that said, I'd get the 5 mtn. I had the WP/copper pass for 5 seasons and it was definitely fun, but the 5 mtn is just that much more versatile. You get the long a basin season, and you get to drive out to cool areas like beaver creek (best vibe of any ski area I've ever been to).
key and breck obviously have the most park options if that's your thing, even vail's park was decent I heard (I'm not not a park skier). not to mention lots of pro's hang around, in case you wanted to meet some or something.